On Monday 12 September 2022 15:48:05 Mike Rapoport wrote: > On Sat, Sep 10, 2022 at 09:39:20AM +0000, Christophe Leroy wrote: > > + Adding Mike who might help if the problem is around memblock. > > > > Le 08/09/2022 à 22:17, Pali Rohár a écrit : > > > On Thursday 08 September 2022 17:35:11 Pali Rohár wrote: > > >> On Thursday 08 September 2022 15:25:14 Christophe Leroy wrote: > > >>> Le 08/08/2022 à 20:40, Pali Rohár a écrit : > > >>>> On Friday 10 June 2022 00:24:20 Pali Rohár wrote: > > >>>>> On Friday 20 May 2022 14:30:02 Pali Rohár wrote: > > >>>>>> + linux-mm > > >>>>>> > > >>>>>> Do you know what are requirements for kernel to support > > >>>>>> non-contiguous > > >>>>>> memory support and what is needed to enable it for 32-bit powerpc? > > >>>>> > > >>>>> Any hints? > > >>>> > > >>>> PING? > > >>>> > > >>> > > >>> The tree following patches landed in powerpc/next branch, so they should > > >>> soon be visible in linux-next too: > > >>> > > >>> fc06755e2562 ("powerpc/32: Drop a stale comment about reservation of > > >>> gigantic pages") > > >>> b0e0d68b1c52 ("powerpc/32: Allow fragmented physical memory") > > >>> 0115953dcebe ("powerpc/32: Remove wii_memory_fixups()") > > >> > > >> Ou, nice! I will try to test it if it allows me to access more than 2GB > > >> of RAM from 4GB DDR3 module with 32-bit addressing mode on P2020 CPU. > > > > > > Hello! Ok, I have tried it from powerpc/next branch, but seems it does > > > not work. I'm getting just early kernel crash. > > > > > > [ 0.000000] CPU maps initialized for 1 thread per core > > > [ 0.000000] (thread shift is 0) > > > [ 0.000000] ----------------------------------------------------- > > > [ 0.000000] phys_mem_size = 0xbe500000 > > > [ 0.000000] dcache_bsize = 0x20 > > > [ 0.000000] icache_bsize = 0x20 > > > [ 0.000000] cpu_features = 0x0000000010010108 > > > [ 0.000000] possible = 0x0000000010010108 > > > [ 0.000000] always = 0x0000000010010108 > > > [ 0.000000] cpu_user_features = 0x84e08000 0x08000000 > > > [ 0.000000] mmu_features = 0x00020010 > > > [ 0.000000] ----------------------------------------------------- > > > mpc85xx_rdb_setup_arch() > > > [ 0.000000] ioremap() called early from of_iomap+0x48/0x80. Use > > > early_ioremap() instead > > > [ 0.000000] MPC85xx RDB board from Freescale Semiconductor > > > [ 0.000000] barrier-nospec: using isync; sync as speculation barrier > > > [ 0.000000] barrier-nospec: patched 182 locations > > > [ 0.000000] Top of RAM: 0xff700000, Total RAM: 0xbe500000 > > > [ 0.000000] Memory hole size: 1042MB > > > [ 0.000000] Zone ranges: > > > [ 0.000000] Normal [mem 0x0000000000000000-0x000000002fffffff] > > > [ 0.000000] HighMem [mem 0x0000000030000000-0x00000000ff6fffff] > > > [ 0.000000] Movable zone start for each node > > > [ 0.000000] Early memory node ranges > > > [ 0.000000] node 0: [mem 0x0000000000000000-0x000000007fffffff] > > > [ 0.000000] node 0: [mem 0x00000000c0200000-0x00000000eeffffff] > > > [ 0.000000] node 0: [mem 0x00000000f0000000-0x00000000ff6fffff] > > > [ 0.000000] Initmem setup node 0 [mem > > > 0x0000000000000000-0x00000000ff6fffff] > > > [ 0.000000] MMU: Allocated 1088 bytes of context maps for 255 contexts > > > [ 0.000000] percpu: Embedded 11 pages/cpu s14196 r8192 d22668 u45056 > > > [ 0.000000] pcpu-alloc: s14196 r8192 d22668 u45056 alloc=11*4096 > > > [ 0.000000] pcpu-alloc: [0] 0 [0] 1 > > > [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: > > > 777792 > > > [ 0.000000] Kernel command line: root=ubi0:rootfs rootfstype=ubifs > > > ubi.mtd=rootfs,2048 rootflags=chk_data_crc rw console=ttyS0,115200 > > > [ 0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 > > > bytes, linear) > > > [ 0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 > > > bytes, linear) > > > [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off > > > [ 0.000000] Kernel attempted to read user page (7df58) - exploit > > > attempt? (uid: 0) > > > [ 0.000000] BUG: Unable to handle kernel data access on read at > > > 0x0007df58 > > > [ 0.000000] Faulting instruction address: 0xc01c8348 > > > [ 0.000000] Oops: Kernel access of bad area, sig: 11 [#1] > > > [ 0.000000] BE PAGE_SIZE=4K SMP NR_CPUS=2 P2020RDB-PC > > > [ 0.000000] Modules linked in: > > > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted > > > 6.0.0-rc2-0caacb197b677410bdac81bc34f05235+ #121 > > > [ 0.000000] NIP: c01c8348 LR: c01cb2bc CTR: 0000000a > > > [ 0.000000] REGS: c10d7e20 TRAP: 0300 Not tainted > > > (6.0.0-rc2-0caacb197b677410bdac81bc34f05235+) > > > [ 0.000000] MSR: 00021000 <CE,ME> CR: 48044224 XER: 00000000 > > > [ 0.000000] DEAR: 0007df58 ESR: 00000000 > > > [ 0.000000] GPR00: c01cb294 c10d7f10 c1045340 00000001 00000004 > > > c112bcc0 00000015 eedf1000 > > > [ 0.000000] GPR08: 00000003 0007df58 00000000 f0000000 28044228 > > > 00000200 00000000 00000000 > > > [ 0.000000] GPR16: 00000000 00000000 00000000 0275cb7a c0000000 > > > 00000001 0000075f 00000000 > > > [ 0.000000] GPR24: c1031004 00000000 00000000 00000001 c10f0000 > > > eedf1000 00080000 00080000 > > > [ 0.000000] NIP [c01c8348] free_unref_page_prepare.part.93+0x48/0x60 > > > [ 0.000000] LR [c01cb2bc] free_unref_page+0x84/0x4b8 > > > [ 0.000000] Call Trace: > > > [ 0.000000] [c10d7f10] [eedf1000] 0xeedf1000 (unreliable) > > > [ 0.000000] [c10d7f20] [c01cb294] free_unref_page+0x5c/0x4b8 > > > [ 0.000000] [c10d7f70] [c1007644] mem_init+0xd0/0x194 > > > [ 0.000000] [c10d7fa0] [c1000e4c] start_kernel+0x4c0/0x6d0 > > > [ 0.000000] [c10d7ff0] [c00003e0] set_ivor+0x13c/0x178 > > > [ 0.000000] Instruction dump: > > > [ 0.000000] 552817be 5509103a 7d294214 55293830 7d4a4a14 812a003c > > > 814a0038 5529002a > > > [ 0.000000] 7c892050 5484c23a 5489eafa 548406fe <7d2a482e> 7d242430 > > > 5484077e 90870010 > > > [ 0.000000] ---[ end trace 0000000000000000 ]--- > > > [ 0.000000] > > > [ 0.000000] Kernel panic - not syncing: Fatal exception > > > [ 0.000000] Rebooting in 1 seconds.. > > > [ 0.000000] System Halted, OK to turn off power > > > > > > 4GB DDR3 SODIMM module is set via Freescale LBC to the whole 4 GB > > > address range. And on ranges: > > > 0x0000_0000 - 0x7fff_ffff > > > 0xc020_0000 - 0xeeff_ffff > > > 0xf000_0000 - 0xff6f_ffff > > > there is no peripheral device, they are free for DRAM. Between these > > > physical ranges are mapped peripheral devices (PCIe and NOR). > > > > > > Any idea if I'm doing something wrong or there can be a bug in memory > > > code? > > > > > > Quite suspicious is that "Initmem setup node 0" prints one range where > > > are also peripherals, not just DRAM. Crash is on address 0xc01c8348 > > > which belongs to PCIe. > > > > > > > Yes I also find that "Initmem setup node 0" suspicious. > > > > However the crash address 0xc01c8348 is valid kernel address. That's a > > virtual address, not a physical address, so that's not PCIe. That's > > kernel linear mapping, so that's likely physical address 0x001c8348 > > offseted by PAGE_OFFSET which is 0xc0000000. > > If I read the dump correctly, 0xc01c8348 is the PC of the instruction that > crashed and the access was to 0x0007df58 which seem to well inside > 0x0000_0000 - 0x7fff_ffff range.
I have tried to read and write memory at address 0x0007df58 in U-Boot and it works fine without any crash. I repeated that boot and it always failed with same errors at same address. I have also tried to use different 4GB DDR module (just in case if it is non-functional) but it failed on the same error on the same address. > And the "Early memory node ranges" look consistent with the memory layout > above. > > My guess would be that something went wrong in the linear map setup, but it > won't hurt running with "memblock=debug" added to the kernel command line > to see if there is anything suspicious there. Here is boot log on serial console with memblock=debug command line: [ 0.000000] memblock_alloc_try_nid: 8 bytes align=0x4 nid=-1 from=0x00000000 max_addr=0x00000000 smp_setup_cpu_maps+0x40/0x2b4 [ 0.000000] memblock_reserve: [0x2fff5d74-0x2fff5d7b] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] CPU maps initialized for 1 thread per core [ 0.000000] (thread shift is 0) [ 0.000000] memblock_phys_free: [0x2fff5d74-0x2fff5d7b] setup_arch+0x1bc/0x318 [ 0.000000] ----------------------------------------------------- [ 0.000000] phys_mem_size = 0xbe500000 [ 0.000000] dcache_bsize = 0x20 [ 0.000000] icache_bsize = 0x20 [ 0.000000] cpu_features = 0x0000000010010108 [ 0.000000] possible = 0x0000000010010108 [ 0.000000] always = 0x0000000010010108 [ 0.000000] cpu_user_features = 0x84e08000 0x08000000 [ 0.000000] mmu_features = 0x00020010 [ 0.000000] ----------------------------------------------------- [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2fff2000-0x2fff3fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2fff0000-0x2fff1fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffee000-0x2ffeffff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffec000-0x2ffedfff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffea000-0x2ffebfff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffe8000-0x2ffe9fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffe6000-0x2ffe7fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffe4000-0x2ffe5fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffe2000-0x2ffe3fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8192 bytes align=0x2000 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_stack+0x2c/0x60 [ 0.000000] memblock_reserve: [0x2ffe0000-0x2ffe1fff] memblock_alloc_range_nid+0xe8/0x1b0 mpc85xx_rdb_setup_arch() [ 0.000000] ioremap() called early from of_iomap+0x48/0x80. Use early_ioremap() instead [ 0.000000] memblock_alloc_try_nid: 4096 bytes align=0x1000 nid=-1 from=0x00000000 max_addr=0x00000000 early_pte_alloc_kernel+0x3c/0x90 [ 0.000000] memblock_reserve: [0x2fff4000-0x2fff4fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] MPC85xx RDB board from Freescale Semiconductor [ 0.000000] barrier-nospec: using isync; sync as speculation barrier [ 0.000000] barrier-nospec: patched 182 locations [ 0.000000] memblock_alloc_try_nid: 4096 bytes align=0x1000 nid=-1 from=0x00000000 max_addr=0x00000000 early_pte_alloc_kernel+0x3c/0x90 [ 0.000000] memblock_reserve: [0x2ffdf000-0x2ffdffff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] Top of RAM: 0xff700000, Total RAM: 0xbe500000 [ 0.000000] Memory hole size: 1042MB [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x000000002fffffff] [ 0.000000] HighMem [mem 0x0000000030000000-0x00000000ff6fffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x000000007fffffff] [ 0.000000] node 0: [mem 0x00000000c0200000-0x00000000eeffffff] [ 0.000000] node 0: [mem 0x00000000f0000000-0x00000000ff6fffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x00000000ff6fffff] [ 0.000000] memblock_alloc_try_nid_raw: 37675008 bytes align=0x20 nid=0 from=0x00000000 max_addr=0x00000000 free_area_init+0x890/0xc94 [ 0.000000] memblock_reserve: [0x2dbf1000-0x2ffdefff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 96 bytes align=0x20 nid=0 from=0x00000000 max_addr=0x00000000 setup_usemap+0x60/0xa0 [ 0.000000] memblock_reserve: [0x2fff5d00-0x2fff5d5f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 416 bytes align=0x20 nid=0 from=0x00000000 max_addr=0x00000000 setup_usemap+0x60/0xa0 [ 0.000000] memblock_reserve: [0x2fff5b60-0x2fff5cff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 32 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 mmu_context_init+0x38/0x154 [ 0.000000] memblock_reserve: [0x2fff5b40-0x2fff5b5f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 1024 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 mmu_context_init+0x7c/0x154 [ 0.000000] memblock_reserve: [0x2fff5740-0x2fff5b3f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 32 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 mmu_context_init+0xc4/0x154 [ 0.000000] memblock_reserve: [0x2fff5720-0x2fff573f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] MMU: Allocated 1088 bytes of context maps for 255 contexts [ 0.000000] memblock_alloc_try_nid: 116 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 start_kernel+0x194/0x6d0 [ 0.000000] memblock_reserve: [0x2fff56a0-0x2fff5713] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 116 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 start_kernel+0x1c0/0x6d0 [ 0.000000] memblock_reserve: [0x2fff5620-0x2fff5693] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 4096 bytes align=0x1000 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_embed_first_chunk+0x314/0x7b4 [ 0.000000] memblock_reserve: [0x2dbf0000-0x2dbf0fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 4096 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_embed_first_chunk+0x4d4/0x7b4 [ 0.000000] memblock_reserve: [0x2dbef000-0x2dbeffff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 90112 bytes align=0x1000 nid=-1 from=0x3fffffff max_addr=0x00000000 pcpu_embed_first_chunk+0x564/0x7b4 [ 0.000000] memblock_reserve: [0x2dbd9000-0x2dbeefff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_phys_free: [0x2dbe4000-0x2dbe3fff] pcpu_embed_first_chunk+0x680/0x7b4 [ 0.000000] memblock_phys_free: [0x2dbef000-0x2dbeefff] pcpu_embed_first_chunk+0x680/0x7b4 [ 0.000000] percpu: Embedded 11 pages/cpu s14196 r8192 d22668 u45056 [ 0.000000] memblock_alloc_try_nid: 4 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_setup_first_chunk+0x37c/0x924 [ 0.000000] memblock_reserve: [0x2fff5d60-0x2fff5d63] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 4 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_setup_first_chunk+0x3a4/0x924 [ 0.000000] memblock_reserve: [0x2fff5600-0x2fff5603] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_setup_first_chunk+0x3cc/0x924 [ 0.000000] memblock_reserve: [0x2fff55e0-0x2fff55e7] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 8 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_setup_first_chunk+0x3f4/0x924 [ 0.000000] memblock_reserve: [0x2fff55c0-0x2fff55c7] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] pcpu-alloc: s14196 r8192 d22668 u45056 alloc=11*4096 [ 0.000000] pcpu-alloc: [0] 0 [0] 1 [ 0.000000] memblock_alloc_try_nid: 136 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_setup_first_chunk+0x7fc/0x924 [ 0.000000] memblock_reserve: [0x2fff5520-0x2fff55a7] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 96 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0x64/0x2e0 [ 0.000000] memblock_reserve: [0x2fff54c0-0x2fff551f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 384 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0xc4/0x2e0 [ 0.000000] memblock_reserve: [0x2fff5340-0x2fff54bf] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 388 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0xf0/0x2e0 [ 0.000000] memblock_reserve: [0x2fff51a0-0x2fff5323] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 96 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0x11c/0x2e0 [ 0.000000] memblock_reserve: [0x2fff5140-0x2fff519f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 96 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0x64/0x2e0 [ 0.000000] memblock_reserve: [0x2fff50e0-0x2fff513f] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 768 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0xc4/0x2e0 [ 0.000000] memblock_reserve: [0x2dbd8d00-0x2dbd8fff] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 772 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0xf0/0x2e0 [ 0.000000] memblock_reserve: [0x2dbd89e0-0x2dbd8ce3] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_alloc_try_nid: 192 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 pcpu_alloc_first_chunk+0x11c/0x2e0 [ 0.000000] memblock_reserve: [0x2fff5020-0x2fff50df] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] memblock_phys_free: [0x2dbf0000-0x2dbf0fff] pcpu_embed_first_chunk+0x744/0x7b4 [ 0.000000] memblock_phys_free: [0x2dbef000-0x2dbeffff] pcpu_embed_first_chunk+0x754/0x7b4 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 777792 [ 0.000000] Kernel command line: root=ubi0:rootfs rootfstype=ubifs ubi.mtd=rootfs,2048 rootflags=chk_data_crc rw console=ttyS0,115200 memblock=debug [ 0.000000] memblock_alloc_try_nid: 524288 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_large_system_hash+0x1a4/0x2ec [ 0.000000] memblock_reserve: [0x2db589e0-0x2dbd89df] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes, linear) [ 0.000000] memblock_alloc_try_nid: 262144 bytes align=0x20 nid=-1 from=0x00000000 max_addr=0x00000000 alloc_large_system_hash+0x1a4/0x2ec [ 0.000000] memblock_reserve: [0x2db189e0-0x2db589df] memblock_alloc_range_nid+0xe8/0x1b0 [ 0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes, linear) [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off [ 0.000000] Kernel attempted to read user page (7df58) - exploit attempt? (uid: 0) [ 0.000000] BUG: Unable to handle kernel data access on read at 0x0007df58 [ 0.000000] Faulting instruction address: 0xc01c8348 [ 0.000000] Oops: Kernel access of bad area, sig: 11 [#1] [ 0.000000] BE PAGE_SIZE=4K SMP NR_CPUS=2 P2020RDB-PC [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc2-0caacb197b677410bdac81bc34f05235+ #121 [ 0.000000] NIP: c01c8348 LR: c01cb2bc CTR: 0000000a [ 0.000000] REGS: c10d7e20 TRAP: 0300 Not tainted (6.0.0-rc2-0caacb197b677410bdac81bc34f05235+) [ 0.000000] MSR: 00021000 <CE,ME> CR: 48044224 XER: 00000000 [ 0.000000] DEAR: 0007df58 ESR: 00000000 [ 0.000000] GPR00: c01cb294 c10d7f10 c1045340 00000001 00000004 c112bcc0 00000015 eedf1000 [ 0.000000] GPR08: 00000003 0007df58 00000000 f0000000 28044228 00000200 00000000 00000000 [ 0.000000] GPR16: 00000000 00000000 00000000 0275cb7a c0000000 00000001 0000075f 00000000 [ 0.000000] GPR24: c1031004 00000000 00000000 00000001 c10f0000 eedf1000 00080000 00080000 [ 0.000000] NIP [c01c8348] free_unref_page_prepare.part.93+0x48/0x60 [ 0.000000] LR [c01cb2bc] free_unref_page+0x84/0x4b8 [ 0.000000] Call Trace: [ 0.000000] [c10d7f10] [eedf1000] 0xeedf1000 (unreliable) [ 0.000000] [c10d7f20] [c01cb294] free_unref_page+0x5c/0x4b8 [ 0.000000] [c10d7f70] [c1007644] mem_init+0xd0/0x194 [ 0.000000] [c10d7fa0] [c1000e4c] start_kernel+0x4c0/0x6d0 [ 0.000000] [c10d7ff0] [c00003e0] set_ivor+0x13c/0x178 [ 0.000000] Instruction dump: [ 0.000000] 552817be 5509103a 7d294214 55293830 7d4a4a14 812a003c 814a0038 5529002a [ 0.000000] 7c892050 5484c23a 5489eafa 548406fe <7d2a482e> 7d242430 5484077e 90870010 [ 0.000000] ---[ end trace 0000000000000000 ]--- [ 0.000000] [ 0.000000] Kernel panic - not syncing: Fatal exception [ 0.000000] Rebooting in 1 seconds.. [ 0.000000] System Halted, OK to turn off power Do you need something more for debug? > > Do you have a way to reproduce this problem under QEMU ? Well, I really do not know how to run it in QEMU. IIRC QEMU does not have support for P2020 processor. Is there any guidance? > > Thanks > > Christophe > > -- > Sincerely yours, > Mike.